Growth dependence of reactively sputtered yttria-stabilized zirconia on Si(100), (110), (111) substrates

Yttria-stabilized zirconia (YSZ) thin films were grown on Si(100), (110) and (Ill)substrates by reactive magnetron sputtering. The deposition was performed in metallic mode using a Zr metal target arranged with Y plates and an aperture for the prevention of target oxidation. By reflection high energy electron diffraction (RHEED) and X-ray diffraction (XRD) analysis, YSZ is found to be epitaxially frown on Si (100) at a substrate temperature of 800 degrees C, indicated by sharp streaks in the RHEED pattern. On the other hand, YSZ films on Si(110) deposited at 600-800 degrees C were all polycrystalline. Although YSZ on Si(lll) showed strong orientational dependence on the substrate, its crystallinity seemed to be degraded by the generation of twin structures. This preferential growth orientation of YSZ was discussed by considering an arrangement of YSZ unit cells on Si substrates with various lattice orientations.